Preparing iron pyrites for desulfurization.



Na- 804,690. PATENTBD NOV. 14, 1905.

U. WEDGE. PREPARING IRON PYRITES FOR DBSULFURIZATION.

APPLICATION FILED HAYG, 1904.

UNITED STATES PATENT OFFICE.

UTLEY WEDGE, OF ARDMORE, PENNSYLVANIA. PREPARING IRON PYRITES FOR DESULFURIZATION.

N 0. 804,690. Specification of Letters Patent. Patented Nov. 14, 1905, Application filed May a, 1904. Serial No. 206.730.

- To all whom it may concern:

Be it known that I, UTLEY \VEDGE, a citizen of the United States, residing in Ardmore, Pennsylvania, have invented certain Improvements in Pro aring Iron Pyrites for Desulfurization, of W 'ch the following is a specification.

The object of my invention is to effect the desulfurization of or prepare for desulfurization that class of iron pyrites known as pyrites fines or pyrites smalls, which contains alarge percentage of the yrites in powdered orpulverulent form and to eflect this object without the necessity of forming the r 5 pyrites into blocks or briquets. Much of the iron pyrites known as yrites fines or pyrites smalls, especial y if it has been leached for the extraction of copper or other metals therefrom, contains such a large percentage of powdered or pulverulent pyrites that it is not susceptible of desulfurization in a mechanical furnace-that is to say, a furnace in which the material is stirred, agitated, or conveyed by mechanicall -operated 2 5 rabbles or stirrers while resting upon a roasting hearth or hearths or by movement of the hearth'itself, since the dust escapes in such quantities as to block or choke the fines or towers used in connection with the furnace 0 even when special settling or dust-collecting I may employ any ordinary form of mixer which will revent the agglomeration of the pyrites in l arge masses, the mixer which I prefer being similar to that shown in the 210- companying drawings, in which Figure 1 represents a longitudinal section of the mixer, and Fig. 2 is a transverse section of the same.

In the drawings, 1 represents a trough of segmental cross-section rovided with a rotating shaft 2, having blades or vanes 3, which exert a combined stirring and feeding pyrites fines and the sulfate of iron or other inding agent being introduced at the head of the trough through suitable feeders 4 and 5 in such pro ortion that the mass only assumes a moderate degree of plasticity, the effect of the mixing and conveying blades or vanes of the device bein to break up any large bodies or lum s of the mixture, so that the properly-unite particles of ore are discharged from the delivery end of the trou 11 in the desired granular or pellet form. e integrity of the grains or pellets may be increased by heating the pyrites, and said heating may be effected while the pyrites is in the mixer by providing the latter with a suitable steam-jacket 6 or other heating appliance, or the granular product may be assed through a special heater of any desire character before being introduced into the de sulfurizing-furnace, or it may, if desired, be conveyed directly from the mixer to said fur 9o nace and may receive its initial heating in the latter. When the preliminary heating of the granular product is effected in the mixer or in a special heater, the temperature should be so low as not to effect any driving 5 off of the sulfur from the pyrites, and in this res ect my invention differs from processes of lum ing iron ore by combining the same with a ux and subjecting the mixture to such high heat as to cause fusion, as such high heat would drive off the sulfur from the pyrites and defeat the purpose of my invention. While I prefer to employ a ferric sulfate as a binder, other binders--such, for instance, as other sulfates of iron or sulfate of copper, sulfate of lead, or sulfate of zinc, or combinations of the same with the sulfate of iron or with each other--may be employed, if desired.

My invention is distinct from that formin 1 :0 the subject of my Patent No. 757,531, dated April 19, 1904, in that I am not compelled to that by adding to said pyrites fines or pyrites smalls containing a: large percentage of powdered or pulverulent pyrites sulfate 3 5 of iron or other binding agent and subjecting the compound to the action of a suitable mixing device the mixture can be made to assume a granular instead of a plastic form, the product being in the form of grains or 40 pellets of irregular sha e and size and the particles composing eac grain or pellet being so firmly united that said grains or pellets can be desulfurized in a mechanical or other furnace without risk of material disintegra- 4 5 tion and without the formation of dust in objectionable quantity. The proportion of sulfate of iron or other binding agent employed will vary, depending upon the physical properties of the pyrites, from one to 50 three or four per cent. being usually required, a high percentage of moisture in the pyrites demanding. a correspondin ly less percentage of binding agent and the percentage of 55 high percentage of powdered or pulverulent form the mass of pyrites into blocks or briquets, the expense of such. briqueting operrites and the binding agent and so treating the compound in the mixer that it will be reduced to and maintained in granular form, whereby its subsequent handling can be effected without the necessity of briqueting.

Having thus described my invention,

claim and desire to secure by Letters Patent 1. The mode herein described of preparing for desulfurization pyrites fines or pyrites smalls composed in part of dust or powder, said mode consisting in mixing the same with a metallic sulfate, and reducing the mixture to and maintaining it in granular form without the a plication of such heat as to drive off sulfur firom the pyrites, substantially as specified.

2. The mode herein described of preparing for desulfurizat-ion pyrites fines or pyrites smalls composed in part of dust or powder, said mode consisting in mixing the same with sulfate of iron, mixture to and maintainin form, substantially as speci e 3. The mode herein described of preparing for desulfurization pyrites fines or pyrites smalls composed in part of dust or powder, said mode consisting in mixing the same with a binding agent, reducing the comound to and maintaining it in granular orm, and subjecting the same to heat insufficient to drive oil the sulfur from the pyrites, substantially as specified.

4. The mode herein described of preparing for desulfurization pyrites fines or pyrites smalls composed in part of dust or powder, said mode consisting in mixing the same with sulfate of iron, reducing the compound to and maintaining it in granular form, and subjecting the same to heat, substantially as specified.

5. The mode herein described of effecting desulfurization of pyrites fines or pyrites smalls, composed in part of dust or it in granular powder,

ation being saved by so combining the py and reducing the form, subjecting the compound to said mode consisting in mixing the same with a metallic sulfate, reducing the compound to and maintaining it in granular form, without the application of such heat as to drive ofi sulfur from the pyrites and then subjecting said granular mass to stirring or agitation upon the hearth of the desulfurizing-furnace, substantially as specified.

6. The mode herein described of effecting desulfurization of pyrites fines or pyrites smalls, composed in part of dust or powder, said mode consisting in mixing the same with sulfate of iron, reducing the compoundto and maintainingit in granularformand then subjecting saidgranular mass to stirring or agitation upon the hearth of the gesiulfurizing-furnace, substantially as speci- 7. The mode herein described of efiecting desulfurization of pyrites fines or pyrites smalls, composed in part of dust or powder, said mode consisting in mixing the same with a suitable binder, reducing the compound to and maintaining it in ranular eat insufficient to drive off sulfur from the pyrites and finally to stirring or agitation upon the hearth of the desulfurizing-furnace, substantially as specified.

8. The mode herein described of efiecting desulfurization of pyrites fines or pyrites smalls, composed in part of dust or powder, said mode consistin in mixing the same with sulfate of iron, re ucing the compound to and maintaining it in granular form, subjecting the compound to heat and finally to stirring or agitation upon the hearth of the desulfurizing-furnace, substantially as specified.

In testimony whereof I have signed -my name to this specification in the presence of two subscribing witnesses.

' UTLEY WEDGE.

Witnesses JAMES MoMoRRIs, Joel H. KLEIN. 

